Beenhaed vojt scheme



UNITED STATES PATENT OFFICE.

BERNHARD VON SCHENK, OF HEIDELBERG, GERMA NY.

SPECIFICATION forming part of Letters Patent No. 231,108, dated August 10, 1880.

Application filed April 17, 1880. (Specimens) To all whom it may concern:

Beitknown that LBERNHARD VON ScHENK, of Heidelberg, Germany, have inventedanew and Improved Composition for Moldings, of which the following is a specification.

My composition is intended for use as a substitute for plaster-of-paris as a material for mannfacturin g various articles by molding or casting.

The composition consists of the followingnamed ingredients, in about the proportions specified: sulphate of lime, nine and one-half parts by weight; powdered coal or coke, one part by weight; iron shales or forgescales, sixty-hundreths of apart by weight. These materials are to be finely powdered and mixed by passing through a fine sieve. Before the coal or coke is added it should be put in water and stirred, so that the larger particles will sink to the bottom. Otherwise the casting will be spotty. The mass is to be mixed in water and manipulated (cast in molds, 850.) in the same manner as plaster of-paris.

The composition has the following advantages: First, articles cast from the composition become as hard as cement; second, the

material sets quicker than plaster-of-paris, can

be cast in anymold,and gives sharp castings; third, the castings are lighter, and the material dries quicker and has more strength than plaster-of-paris; fourth, the mass can be used for all purposes requiring plastic materials, it is easily worked, will not freeze, and when painted with oil resists the action of the weather; fifth, oil-paints take firm hold of the cast material, and the surface may be washed with soap and water without injury; and, sixth, the color is warmer than pure plaster castings, which is of importance with models that are to be drawn from.

Having thus described my invention, I claim as new and desire to secure by Letters Patent A composition of matter consisting of sulphate of lime nine and one-half parts, coal or coke one part, and iron shales sixty-hundredths of a part, prepared as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

BERNHARD VON SOHENK.

Witnesses:

J. ENGLERT, MULBRY. 

